All of the sizes are the same other than the rail lengths. I opted for the 25” one because my Delta Homecraft TS is pretty small. It came with only a few token wads of newdpaper to protect it, and the main knob was broken because of it. This one uses a rear rail, which I like and have not mounted yet. It also works well so far without the rear rail attached. The first pic shows what it came with: a bag of hardware, a rear rail, the fence, the front rail, and no instructions. You c...